Executable XML users challenge

provide any LISP macro with clear explanation of its structure and function
that is :
1.concise (max 10 lines)
2.does not have a C equivalent(at least not anything above 100 lines)
3.does not use any libraries or imported complex functions which are not in C
If you provide an exact explanation/commentary on what it does i'll try to make a C solution which
is equivalent to LISP one. If i fail to do so, LISP wins, if i provide a solution you can make another macro.
If all examples in the thread are provide with C equivalents, LISP loses.

>>207
If i was was designing languages everytime i program my productivity will be zero, since i would be designing the perfect language [...]
It's not always a 'perfect' language, it's just what maps best to your mental model of the problem.
Of course since my Perfect language is so complex, only i could read it and only if don't forget the entire language.
Complex? Why?
i.e. your macro layer is inferior,convoluted version of void.h(which includes reusable functions)
This is just hilarious.
would be neglected, unoptimized mess which i would think of not as a living, running program but as bunch of meaningless strings my Perfect Language would transform into the perfect program.

As a matter of fact, here's some real-world situation of how development proceeded on a mid-sized project that I wrote a while ago:
- 2 days (on and off) to write about 1500 LoC of CL, about 300 written in a DSL, and the DSL implementation itself wasn't too big (some 200 LoC)
- Initial performance not bad (some 10-20 times slower than I would expect in C), at least for what it was meant to be used for (PHP or Ruby would be much slower for this).
- I decide to profile. After about 30 minutes of optimizing the functions profiling identified as being executed often and being slow, prformance was increased immensely (various algorithms were slightly changed to reduce their time complexity). Performance 1.5-3 times slower than C, way beyond what I actually needed for the task at hand.

Had I chosen to write that in C, it would have taken me a week to write and I estimate about 10KLOC and I would have to cringe each time I would have had to edit all the repetitive code that I would have to write by hand (autogenerated in my Lisp version).

In the end, I really don't care what you think about Lisp, I only care about what Lisp can do for me, but I do find all this Lisp-bashing that's been going on around here lately a bit hilarious. It's a bit like having some piece of locally verifiable truth ("theorem") for yourself (which you use for practical things) and then you have some people claiming that that trivial truth is false (and they can't use that truth("theorem") to attain some particular shortcuts, so their life is harder) - I see it as people making their own lifes more difficult than they have to and thinking their life is actually less difficult than my own - I can only pass by smiling and move on with my business.

Have fun with your void~